A Diagnostic Biomarker for Cervical Myelopathy Based on Dynamic MRI.

STUDY DESIGN

Multicenter prospective observational study.

OBJECTIVE

Diffusion tensor imaging (DTI) in flexion-extension improves the diagnosis of degenerative cervical myelopathy (DCM). We aimed to provide an imaging biomarker for the detection of DCM.

SUMMARY OF BACKGROUND DATA

DCM is the most common form of spinal cord dysfunction in adults; however, imaging surveillance for myelopathy remains poorly characterized.

METHODS

Symptomatic DCM patients were examined in maximum neck flexion-extension and neutral positions in a 3T-MRI scanner and allocated to two groups: i) patients with visible intramedullary hyperintensity (IHIS) on T2-weighted imaging (IHIS+, n=10); and ii) patients without IHIS (IHIS-, n=11). Range of motion, space available for the spinal cord, apparent diffusion coefficient (ADC), axial diffusivity (AD), radial diffusivity (RD), and fractional anisotropy (FA) were measured and compared between the neck positions and between the groups as well as between control (C2/3) and pathological segments.

RESULTS

Significant differences between the control level (C2/3) and pathological segments were appreciated for the IHIS+group at neutral neck position in AD; at flexion in ADC and AD; and at neck extension in ADC, AD, and FA values. For the IHIS- group, significant differences between the control level (C2/3) and pathological segments were found only for ADC values in neck extension. When comparing diffusion parameters between groups, RD was significantly different in all three neck positions.

CONCLUSION

Significant increases in ADC values between the control and pathological segments were found for both groups in neck extension only. This may serve as a diagnostic tool to identify early changes in the spinal cord related to myelopathy and to indicate potentially reversible spinal cord injury and support the indication for surgery in select circumstances.